Chuck



O. MANN oct. 2,1951

CHUCK vFiled July 2o, 1949' INVENTOR: OLIVER MANN .""`lllillllll`ill\ ATTORNEY,

Patented Oct. 2, 1951 CHUCK Oliver Mann, Danvers,.Mass., assigner to Sylvania Electric Products Inc., Salem, Mass., a corporation of Massachusetts 1 'Application July 20, 1949, serial No. 105,796

This invention relates to article-holding mechanisms and more particularly to chucks for accurately positioning and positively securing an article.

In the manufacture of electric lamps and discharge devices, such as radio tubes and the like, an elongated glass tube, hereinafter referred to as an exhaust tube, is commonly employed to provide a means through which the envelope of the lamp or discharge device may be evacuated. This exhaust tube usually is an integral part of a mount which includes the electrode which is sealed within the lamp or discharge device envelope.

In the sealing operation,i. e., the operation wherein the electrode mount is secured or joined to the envelope, it is necessary that the mount be accurately positioned with reference to the envelope in order to insure proper disposition of the electrode therein upon completion of this operation. This is particularly true with reference to projection lamps which employ electrodes of the lamentary type.

Accordingly, therefore, a particular object of this invention is to provide a mechanism for accurately positioning a lamp mount with reference to the lamp envelope during the sealing operation.

Another object is to provide a means for positioning and securing the exhaust tube of a lamp y mount whereby the accurate disposition of the mount with reference to the envelope is insured.

Further objects, advantages and features will be apparent from the following description when read in conjunction with the accompanying drawing in which:

Fig. 1 is a side elevational view partly in section of a sealing head assembly with the chuck thereof in the position of' engagement.

Fig. 2is a side elevational view partly in section of a sealing head assembly with the chuck thereof in the position of disengagement.

Fig. 3 is a sectional View of the chuck taken along the longitudinal axis thereof, with the exhaust tube in position.

Fig. 4 is a sectional view of the chuck taken along the lines 4--4 of Fig. 3.

Fig. 5 is a sectional view of the chuck taken along the lines 5-5 of Fig. 1.

The sealing head chuck of my invention comprises a pair of slides disposed on the sealing head spindle and in register with one another thereon, and two sets of three standard ballbearing balls disposed in apertures therefor in the spindle and enclosed by their respective slides.

3 Claims. (Cl. 279-75) In Figures 1 and 2 the sealing head assembly is mounted on a turret I, a fragmentary portion of which is shown. The turret Il is a part of a conventional lamp sealing machine designed to eifect the advancement of the lamp mount and lamp envelope past a plurality of stations thereon to accomplish the sealing operation. Actuation of the sealing head, which is effected at certain of these stations, is accomplished by means of a cam track 2, motion being imparted to the head through a spindle 3. The spindle 3 extends through an aperture il. therefor in the turret I. A collar 5, which is mounted on the turret I and in register with the aperture 4, serves as the base for the chuck 6, of my invention. The chuck 6 comprises a pair of slides I and 8, in register with one another, which coact with two sets of three standard ball-bearing balls 9 and I0 disposed in apertures therefor in the spindle 3. The inside faces of slides 'I and 8 are frustro-conical in contour. The upper portion of the spindle 3 is provided with a sleeve II which has apertures therein to permit the balls 9 and I0 to engage the inside face of slides l and 8.

The top of the spindle 3 is provided with a sealing pin I2 (Figure 3) on which an electrode mount I3 (a portion of which is shown) is seated. That portion of the mount I3 which is shown comprises a flare I4, a stern press I5, electrodesupporting wires I 6 and an exhaust tube I'I. The exhaust tube |"I is disposed in an opening I8 therefor in the spindle 3.

In Figure 2, the sealing head assembly is shown in the position which it assumes during loading and unloading, i. e., at the start of the sealing operation and at the conclusion thereof. A mount I3 is positioned on the sealing head by threading the exhaust tube I'I thereof into the opening I 8 in the spindle 3 until the are III seats itself on the sealing pin I2. The lamp envelope (not shown) to which the mount is to be sealed is securely positioned above the mount with the periphery of the neck of the envelope in engagement with the flare Ill. As the sealing head moves from the loading station as shown in Figure 2 to the next station on the sealing machine, the spindle 3 is caused to move upwardly by a rise in the cam track 2. Since the balls 9 and I0 are disposed in the spindle, they move upwardly therewith. The internal taper of the slides 1 and 8 is such that the balls 9 and I0 engage the inside faces thereof and the exhaust tube II as the spindle 3 approaches the end of its upward stroke.

A collar I9 is ixedly attached to the spindle 3 to insure a predetermined upper limit of the serves as a stop to limit the upward travel of 5 slide 8 on the spindle.

Figure 3 shows the relative disposition of the several partsvof,l the: sealing head assembly after: the chuck has engagedthe exhaust tube l1. Figures 3 and 4 show how uniform Vertical align- 10 ment and concentricity is attained and insured.. Vertical alignment is obtained by reason of the, fact that two sets of three balls in two suitably spaced horizontal planes provide sixzpositivepointt contacts. Concentricity is assured because: all l5T three of the balls in each set thereof are of the same size; they all engage theexhaust/tubey at` substantially the same instant, and with substantially equal forces, since each set of balls is'act'uated by its own slide. The positive gripping of 20 the' exhaust tube,. whichv the, chuck of1 my.: invention:l insures, not only: provides uniform4 vertical alignment and concentricity during they initial:` states vof Y the sealingl operation, but italso makes,`

possible-,Working of the molten glass. to: actually 25 form .theseal during, the: later stagesV of the; sealA ingzcycle.

What I claiIrL-is;`

1. In anV article--l'ioldingA apparatus, the 'combi-1 nation'J of azspindle` having. aperturesv in the side 30! wall'` thereof: and an articlereceivng openingA thereinzextendinglfrom an end thereof;l alpair of independent. slides disposed onv said spindle, andA concentric therewith and: in register: with one.:

another,. theinnerY face of each" of said slides 35- lf,5'l57,706.;

beingfrustrorconical in contour; said slidesbeing;

moveable vertically on said spindle; and a plurality of balls seated in apertures therefor in said spindle and partially extending into the space defined by the frustro-conical inner face of said slides.

2. A chuck for gripping the exhaust tube of an electric lamp disposed in a spindle therefor, said chuck comprisingtwo sets, of'ballssdisposed about theperi'phery of the spindledn two separate locations along the longitudinal axis thereof; and a pair of independent slides disposed on said spindle and moveable vertically thereon, each of said slides enclosing a set of said balls, the inner face ofz'each'aof.saidslidesfbeing frustro-conical in contour;

3i Inan'article-'fholding apparatus, the combination of'K a-spindle having apertures in the side wall thereof and an elongated article-receiving openingtherein extending from an end thereof; a plurality of balls seated in the apertures in said spindle;y and'. apairr oft independent. slides` concentric ,withisaidi spindleand enclosing said; balls;A the internallfacesofisaid slidesbeing substantially.l frustro-conical in contour, said slides being move-- able verticallyfonlsaidspindle;.

OLIVER: MANN;

REFERENCESA CITED They following references are of record in the le of thispatent:

UNITED, STATES.- PATENTS,

Number: Name: Date' 1,130,716 Dressel Mar. 91915/ Whitmorefet, al; July 28, 1925 

